EP4500624A1

EP4500624A1 - A housing for a battery module

Info

Publication number: EP4500624A1
Application number: EP23713938.1A
Authority: EP
Inventors: Anneke Swierstra; Kilian MENZL
Original assignee: Northvolt Systems AB
Current assignee: Scania Industrial Batteries AB
Priority date: 2022-03-30
Filing date: 2023-03-28
Publication date: 2025-02-05
Also published as: WO2023186909A1; SE2250392A1

Abstract

The present invention relates a housing (70) for a battery module (10) defining one or more compartments, each compartment is configured to house a plurality of battery cells (5), the one or more compartments is delimited by a plurality of walls (11, 12, 15), wherein at least one of the plurality of walls comprises: a first layer provided with one or more grooves (24) facing each compartment; and a second layer (21) arranged over the one or more grooves (24) in the first layer to form at least one cooling channel adjacent to each compartment. The housing further comprises: a cooling medium inlet (13) configured to introduce a cooling medium into each of the at least one cooling channel; and a cooling medium outlet (14) configured to let the cooling medium out of each of the at least one cooling channel.

Description

A HOUSING FOR A BATTERY MODULE

TECHNICAL FIELD

The present disclosure relates to the field of battery modules, and more particular to battery modules for electric applications.

BACKGROUND

It is common to implement a system for cooling of a battery module, either separately or when mounted in a battery pack together with several battery modules. Cooling plates including cooling channels may be thermally attached to one or more sides of a battery module with a purpose to provide cooling to the battery cells, e.g. cylindrical cells or prismatic cells.

A drawback with using a separate cooling plate is that the module frame housing the battery cells creates a thermal barrier between the cooling channels and the battery cells, which reduces the cooling efficiency.

Thus, there is a need to improve the cooling efficiency of the battery cells when mounted in a battery module.

SUMMARY

An object of the present disclosure is to provide structural details of a battery module which seeks to mitigate, alleviate, or eliminate one or more of the above-identified deficiencies in the art and disadvantages singly or in any combination.

This object is obtained by a housing for a battery module defining one or more compartments, each compartment is configured to house a plurality of battery cells, and the one or more compartments is delimited by a plurality of walls. At least one of the plurality of walls comprises a first layer provided with one or more grooves facing each compartment, and a second layer arranged over the one or more grooves in the first layer to form at least one cooling channel adjacent to each compartment. The housing further comprises a cooling medium inlet configured to introduce a cooling medium into each of the at least one cooling channel, and a cooling medium outlet configured to let the cooling medium out of each of the at least one cooling channel. An advantage with the present invention is that a more efficient cooling of the battery cells within each compartment may be achieved since the cooling channels are in close proximity of the battery cells within the housing.

Another advantage is that the present invention is less expensive than using a separate cooling plate.

This object is also obtained by a battery module comprising a housing defining one or more compartments and a plurality of battery cells arranged in the one or more compartments.

An advantage with the battery module is that a battery module with a compact cooling solution is obtained, since the cooling channels are integrated in the battery module housing adjacent to the battery cells.

Further aspects and advantages may be obtained by a skilled person from the detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing will be apparent from the following more particular description of the example embodiments, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the example embodiments.

Figure 1 is a perspective view of a first example embodiment of a battery module;

Figure 2 is a sectional view of a part of the battery module of Figure 1;

Figure 3a is an exploded perspective view of an alternative to the first example embodiment of the battery module of Figure 1;

Figure 3b is a sectional view of a part of the battery module of Figure 3a;

Figure 4 is a sectional view of a part of a second example embodiment of a battery module;

Figure 5a is a sectional view of a third example embodiment of the battery module;

Figure 5b is a sectional view of an alternative embodiment of the third example embodiment of the battery module of Figure 5a;

Figure 6 is perspective view of a first example embodiment of frame for a battery module;

Figure 7 is a perspective view of a housing with a frame of Figure 6 and a plate; Figure 8 is perspective view of a second example embodiment of casing for a battery module; Figure 9a is perspective sectional view of a second example embodiment in Figure 8;

Figure 9b illustrates cooling medium interconnection between battery modules with a cooling manifold, as illustrated in Figure 8 and 9a;

Figure 10 is a sectional view of a fourth example embodiment of a battery module; and

Figure 11 is a sectional view of an alternative embodiment of the fourth example embodiment of the battery module of figure 10.

DETAILED DESCRIPTION

Aspects of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings. The apparatus disclosed herein can, however, be realized in many different forms and should not be construed as being limited to the aspects set forth herein. Like numbers in the drawings refer to like elements throughout.

The terminology used herein is for the purpose of describing particular aspects of the disclosure only, and is not intended to limit the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Some of the example embodiments presented herein are directed towards battery housings with cooling arrangements. The battery housing is part of a battery module that comprises battery cells, which may be cylindrical or prismatic cells (in particular lithium-ion secondary battery cells).

This disclosure is related to a battery module where cooling channels are integrated into the housing of the battery module instead of having a separate cooling plate for cooling the battery cells within the battery module. As an example, the cooling channels may be injection-molded directly into the bottom wall of the module if the module frame is made of plastic or other moldable material. The cooling channels may be molded as "half-pipes" and a thermally conductive plate is placed on top to close the channels. The plate may be made of aluminum or other suitable material with high thermal conductivity.

An advantage of this solution is that it is less expensive than using a separate cooling plate. Figure 1 is an perspective view of a battery module 10 and Figure 2 is a sectional view of the same battery module where some parts, such as a current collector grid, have been omitted. The battery module 10 comprises a housing having side walls 11, a top wall 12 and a bottom wall 15 delimiting a single compartment housing a plurality of battery cells 5. The bottom wall and the side walls form a module frame 20 having a lateral wall, and the side walls 11 are arranged around the periphery of the lateral wall, i.e. the bottom wall 15, which in this example is provided with cooling channels. The bottom wall 15 comprises a first layer, in this example the first layer is the module frame 20, provided with grooves 24 facing the compartment indicated by 25 in Figure 2, and a plate 21 acting as a second layer arranged over the grooves 24 to form cooling channels adjacent to each compartment.

The battery cells 5 are arranged in close proximity to the plate 21 to provide cooling to the battery cells 5 when a cooling medium is transported through the cooling channels. A cell holder 22 is provided on the plate 21 to position and provide a distance between the battery cells 5.

The first layer, e.g. the module frame 20, is preferably made of a material that has a lower electric conductivity than the material of the plate 21, and the first layer may for instance be made of a polymer. The second layer, e.g. the plate 21, may be made of a material that has a higher thermal conductivity than the material of first layer. As an example, the plate 21 may be a sheet of a metal alloy or an aluminium alloy. However, it is important that electrical insulation is provided between the battery cells 5 in case the plate 21 is made from a material which is electrically conductive. This is illustrated in Fig 3a and 3b.

The housing further comprises a cooling medium inlet 13 configured to introduce a cooling medium into each of the at least one cooling channel, and a cooling medium outlet 14 configured to let the cooling medium out of each of the at least one cooling channel.

Figure 3a is an exploded perspective view of an alternative design of the battery module 10 of Figure 1 comprising a module frame 30, the plate 21, an alternative cell holder 23, battery cells 5, terminals 32, 33 electrically connected to the battery cells 5 via a collector plate 31 and a lid 12. The bottom wall of the module frame 20 is in this example provided with grooves 24 which are covered by the plate 21 to create the cooling channels. Figure 3b is a sectional view of a part of the assembled battery module 30 of Figure 3a, where one battery cell 5 is placed in the alternative cell holder 23 on top of the plate 21. The cooling channel is in this example directly situated below the battery cell 5 when placed in a hole of the alternative cell holder 23. The alternative cell holder is a sheet provided with holes where a cylindrical cell can fit. The holes in the alternative cell holder 23 are provided with a flange which forms a shelf for the battery cell to rest on. A thermal interface material, TIM, 34 is provided in the gap underneath the battery cell 5. The TIM 34 and the gap provide both thermal connection and electrical insulation between the battery cell 5 and the plate 21.

The module frame 20 is preferably made of a material that has a lower electric conductivity than the material of the plate 21, and the module frame may for instance be made of a polymer. The plate 21 may be made of a material that has a higher thermal conductivity than the material of module frame 20. As an example, the plate 21 may be a sheet of a metal alloy or an aluminium alloy. The flange in the holes of the alternative cell holder 23 can provide the required electrical insulation between the battery cells 5 together with thee TIM 34 in case the plate 21 is made from a material which is electrically conductive.

Figure 4 is a sectional view of a part of a battery module 40 comprising a module frame having a bottom wall 15 provided with grooves 24 and side walls 41 provided with grooves 44. A plate 21 is placed on the bottom wall facing the compartment (indicated by 25) and side plates 43 are placed against the inside of the side walls 41 (as indicated by 48 and 49), thereby creating cooling channels at the bottom wall 15 and at the side walls 41. A stack of prismatic battery cells 45 is in this example provided in the compartment 25 defined by the bottom wall 15, side walls 41 and top wall 12. The top side of the prismatic cells 45 may also comprise terminals 47 and exhaust valves (not shown). For completeness, it is noted that a battery module may comprise additional components under the lid 12, which are not shown in Figure 4 in order to not obscure the inventive concept. For example, the cell terminals are typically attached to bus bars, e.g. via welding, in order to provide an electrical connection with the cells to enable charging and discharging. A cell sensing assembly may be provided on top of the cell stack with temperature and/or voltage sensors which are attached to the cells or bus bars e.g. using a wire harness.

Figure 5a is a sectional view of a battery module 50 defining a first compartment 52 and a second compartment 53, each compartment is configured to house a plurality of battery cells 5. The first and second compartment are delimited by a shared lateral wall 56, side walls 51 arranged around the periphery of the shared lateral wall 56 and separate lids 12. The first layer, i.e. the shared lateral wall 56, is provided with cooling channels created by through-going grooves 54 in the shared lateral wall 56 and a second layer, i.e. the first plate 21, arranged overthe through- going grooves 54 in the first compartment 52 and a third layer, i.e. a second plate 57, arranged over the through-going grooves 54 in the second compartment 53. The alternative cell holders

23 are provided on top of the first plate 21 and second plate 57 for the battery cells 5 and TIM may be provided between each battery cell and the respective plate 21, 57. The second plate 57 is preferably made of a material corresponding to the material of the first plate 21.

Although not illustrated, the housing is also provided with a cooling medium inlet configured to introduce a cooling medium into each of the at least one cooling channel, and a cooling medium outlet configured to let the cooling medium out of each of the at least one cooling channel.

Figure 5b is a sectional view of an alternative embodiment 58 of the battery module of Figure 5a. In Figure 5a, the cooling channels are provided by through-going grooves 54 in the shared wall 56 of the first compartment 52 and the second compartment 53. In Figure 5b, a first set of cooling channels is provided by grooves 59a arranged adjacent to the first compartment 52 and a second set of cooling channels is provided by grooves 59b arranged adjacent to the second compartment 53. Thus, the through-going grooves 54 has been replaced by two sets of grooves 59a and 59b facing each respective compartment.

Figure 6 is perspective view of a module frame 61 for a battery module provided with grooves

24 on the bottom wall 62 of the module frame 61. The module frame 61 is also provided with a cooling medium inlet 13 configured to introduce a cooling medium into each of the at least one cooling channel, and a cooling medium outlet 14 configured to let the cooling medium out of each of the at least one cooling channel. Figure 7 is a perspective view of a housing 70 comprising a module frame 61 of Figure 6 and a plate 21 mounted to the bottom surface inside the module frame 61. The bottom wall 71 of the housing comprises in this example a first layer, i.e. the bottom wall 62 of the module frame 61, and a second layer, i.e. the plate 21.

Figure 8 is perspective view of an alternative version of a module frame 81 for a battery module provided with grooves 84 on the bottom wall and reinforcements 85 on the side walls. The module frame 81 is also provided with an input manifold 82 in communication with the cooling medium inlet, and an output manifold 83 in communication with the cooling medium outlet.

Figure 9a is perspective sectional view of the module frame 81 in Figure 8 further illustrating an example embodiment of the input manifold 82, and figure 9b illustrates the cooling medium interconnection of between stacked battery modules 80. The outlet manifold is not illustrated in Figure 9a, but has a similar design to collect cooling medium from the battery module. A first opening 91 is configured to receive cooling medium which is forwarded to a second opening 92 and via a branch 93 to the grooves 84 being a part of the cooling channels of the battery module. The second opening 92 may be in communication with a first opening of another battery module 80 to further distribute cooling medium as indicated by the interconnection piece 94 in Figure 9b, or the second opening 92 may be closed with an end piece 95. When closed, all cooling medium will be directed into the cooling channels of the last battery module 80 to the outlet manifold (not shown).

Figure 10 is a sectional view of a part of another example embodiment of a battery module 100. This example embodiment also comprises cooling channels integrated in the module frame. However in addition to this, there are also venting channels provided in the module frame to prevent thermal runaway and add safety to the battery module. In this example, the bottom wall of the venting channel is adapted to burst if there is a pressure increase.

The solution is specifically adapted to be used with battery cells which have a vent facing the bottom of the module (could be either cylindrical or prismatic cells). The advantage is increase safety while keeping the manufacturing cost and complexity down as no additional parts are needed.

The battery module 100 comprises a first layer implemented as a lateral wall 115 (e.g. a bottom wall or a top wall) provided with grooves 24 and a plate 103 to create cooling channels for cooling battery cells 5. The plate 103 is provided with holes that are aligned with the holes in the cell holder 23 when mounted to the plate 103, and the lateral wall 115 is further provided with pressure relief cavities 102 that are aligned with the holes in the plate 103. An opening 107 of each pressure relief cavity 102 is configured to be positioned adjacent to a pressure relief valve (not shown) of each of the plurality of battery cells 5, and each pressure relief cavity 102 further comprises an evacuation wall 106 configured to burst when pressure increases above a predetermined threshold in the pressure relief cavity 102. In this example the pressure relief cavity 102 is integrated into the lateral wall 115 and the evacuation wall 106 of the pressure relief cavity is also integrated into the lateral wall. A TIM 104 may be provided between the battery cell 5 and the cell holder 23 to increase the cooling efficiency since the grooves 24 for the cooling channels no longer are provided directly below the battery cells.

Figure 11 is a sectional view of an alternative embodiment of the battery module of figure 10 where cell spacers 105 are provided to prevent short-circuiting battery cells 5.

This disclosure relates to a housing for a battery module defining one or more compartments, each compartment is configured to house a plurality of battery cells, wherein the one or more compartments is delimited by a plurality of walls. At least one of the plurality of walls comprises: a first layer provided with one or more grooves facing each compartment; and a second layer arranged over the one or more grooves in the first layer to form at least one cooling channel adjacent to each compartment. The housing further comprises: a cooling medium inlet configured to introduce a cooling medium into each of the at least one cooling channel; and a cooling medium outlet configured to let the cooling medium out of each of the at least one cooling channel.

According to some aspects, the plurality of walls comprises a lateral wall and a plurality of side walls arranged around the periphery of the lateral wall, wherein the lateral wall is provided with cooling channels.

According to some aspects, the housing defines a single compartment.

According to some aspects, the lateral wall is a bottom wall or a top wall.

According to some aspects, the housing comprises a first compartment and a second compartment and the at least one cooling channel is provided in a shared wall of the first compartment and the second compartment.

According to some aspects, a first set of the at least one cooling channel is adjacent to the first compartment and on a second set of the at least one cooling channel faces is adjacent to the second compartment. According to some aspects, the first layer of the shared wall is provided with through-going grooves and the second layer is arranged over the through-going grooves adjacent to the first compartment, and the shared wall further comprises a third layer arranged over the through- going grooves adjacent to the second compartment to form a common cooling channel of the at least one cooling channels.

According to some aspects, the third layer is made of a material corresponding to the material of the second layer.

According to some aspects, the first layer is made of a material that has a lower electric conductivity than the material of the second layer.

According to some aspects, the first layer is made of a polymer.

According to some aspects, the second layer is made of a material that has a higher thermal conductivity than the material of first layer.

According to some aspects, the second layer is made of a metal alloy or an aluminium alloy.

According to some aspects, the housing further comprising an input manifold in communication with the cooling medium inlet of the at least one cooling channel and an output manifold in communication with the cooling medium outlet of the at least one cooling channel.

According to some aspects, the housing is further provided with a plurality of pressure relief cavities, wherein an opening of each pressure relief cavity is configured to be positioned adjacent to a pressure relief valve of each of the plurality of battery cells, and each pressure relief cavity further comprises an evacuation wall configured to burst when pressure increases above a predetermined threshold in the pressure relief cavity.

According to some aspects, the pressure relief cavity is integrated into the first layer.

According to some aspects, the evacuation wall of the pressure relief cavity is integrated into the first layer.

The present disclosure also relates to a battery module comprising a housing as defined above and a plurality of battery cells arranged in the one or more compartments. The description of the example embodiments provided herein have been presented for purposes of illustration. The description is not intended to be exhaustive or to limit example embodiments to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of various alternatives to the provided embodiments. The examples discussed herein were chosen and described in order to explain the principles and the nature of various example embodiments and its practical application to enable one skilled in the art to utilize the example embodiments in various manners and with various modifications as are suited to the particular use contemplated. The features of the embodiments described herein may be combined in all possible combinations of apparatus, modules and systems. It should be appreciated that the example embodiments presented herein may be practiced in any combination with each other.

It should be noted that the word "comprising" does not necessarily exclude the presence of other elements or steps than those listed and the words "a" or "an" preceding an element do not exclude the presence of a plurality of such elements. It should further be noted that any reference signs do not limit the scope of the claims, and that several "means", "units" or "devices" may be represented by the same item of hardware.

In the drawings and specification, there have been disclosed exemplary embodiments. However, many variations and modifications can be made to these embodiments. Accordingly, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the embodiments being defined by the following claims.

Claims

1. A housing (70) for a battery module (10) defining one or more compartments, each compartment is configured to house a plurality of battery cells (5), the one or more compartments is delimited by a plurality of walls (11, 12, 15; 41; 51, 56), wherein at least one of the plurality of walls comprises: a first layer provided with one or more grooves (24; 44) facing each compartment; and a second layer (21; 43) arranged over the one or more grooves (24; 44) in the first layer to form at least one cooling channel adjacent to each compartment; wherein the housing further comprises: a cooling medium inlet (13) configured to introduce a cooling medium into each of the at least one cooling channel; and a cooling medium outlet (14) configured to let the cooling medium out of each of the at least one cooling channel.

2. The housing according to claim 1, wherein the plurality of walls comprises a lateral wall (15; 56) and a plurality of side walls (11; 41; 51) arranged around the periphery of the lateral wall (15; 56), wherein the lateral wall is provided with cooling channels.

3. The housing according to claim 1 or 2, wherein the housing defines a single compartment.

4. The housing according to any of claims 2-3, wherein the lateral wall is a bottom wall (15) or a top wall.

5. The housing according to claim 1 or 2, wherein the housing comprises a first compartment and a second compartment and the at least one cooling channel is provided in a shared wall (56) of the first compartment and the second compartment.

6. The housing according to claim 5, wherein a first set of the at least one cooling channel is adjacent to the first compartment and on a second set of the at least one cooling channel is adjacent to the second compartment.

7. The housing according to claim 5, wherein the first layer of the shared wall (56) is provided with through-going grooves (54) and the second layer (21) is arranged over the through-going grooves (54) adjacent to the first compartment, and the shared wall (56) further comprises a third layer (57) arranged over the through-going grooves (54) adjacent to the second compartment to form a common cooling channel of the at least one cooling channels.

8. The housing according to claim 7, wherein the third layer (57) is made of a material corresponding to the material of the second layer (21).

9. The housing according to any of claims 1-8, wherein the first layer is made of a material that has a lower electric conductivity than the material of the second layer (21).

10. The housing according to claim 9, wherein the first layer is made of a polymer.

11. The housing according to any of claims 1-10, wherein the second layer (21) is made of a material that has a higher thermal conductivity than the material of first layer.

12. The housing according to claim 11, wherein the second layer (21) is made of a metal alloy or an aluminium alloy.

13. The housing according to any of claims 1-12, wherein the housing further comprising an input manifold (82) in communication with the cooling medium inlet of the at least one cooling channel and an output manifold (83) in communication with the cooling medium outlet of the at least one cooling channel.

14. The housing according to any of claims 1-13, wherein the housing is further provided with a plurality of pressure relief cavities (102), wherein an opening (107) of each pressure relief cavity (102) is configured to be positioned adjacent to a pressure relief valve of each of the plurality of battery cells (5), and each pressure relief cavity (102) further comprises an evacuation wall (106) configured to burst when pressure increases above a predetermined threshold in the pressure relief cavity (102).

15. The housing according to claim 14, wherein the pressure relief cavity is integrated into the first layer (115).

16. The housing according to claim 15, wherein the evacuation wall (106) of the pressure relief cavity is integrated into the first layer (115).

17. A battery module comprising a housing according to any one of claims 1-16 and a plurality of battery cells (5) arranged in the one or more compartments.